When dry camping, I almost always end up with a full grey water tank and an almost empty black water tank. Especially when I can get more water while I am parked.

At OSH we had the honey wagon come by and pump the tanks out, but if I could have transferred some of the grey water to the black water tank, I could have probably made it a couple of more days and not had to wait around for the truck.

However, when the truck came, the honey wagon man just reached down and spun the discharge outlet to the side and hooked it up. I didn't realize you could move it. In fact, the guy said most of them are rigged up to be moved.

So fast forward to the time at which Mike, Tom, Brent and I have the hose stretched out from the water well to fill up the coaches. Mike has a short hose (6") that has a valve in it. After looking at that hose, I got to thinking, since my sewer outlet has a cap that has a water hose connection / cap on it, why couldn't I just install the short hose with the little valve on the cap and then open both tanks up and let them crossfeed. Then when it was done, I could close one side and hook water up to the short hose and flush the "WYE" out with clean water, then switch sides and flush the other side out then close it and drain the remaining semi clean water out before hooking up my sewer hose and draining the whole load.

Does this seem workable or has anyone else done it or did you figure an alternative method to crossfeed them without having that little bit of honey trapped between the two valves and the discharge cap?